GCT logo.jpg

May 2018






Our company is controlling patents and Know-How of a solar technology named Hybrid PV+Solar Chimney technology (HPVSC technology). Details of the HPVSCtechnology are shown in our site




The HPVSC technology is a revolutionary version of the conventional solar chimney technology, with which we can generate electricity by PV panels placed on the roof of a proper greenhouse and by air turbines, using the solar chimney air up-drafting effect. Furthermore, the greenhouse of these plants can be used for protected hydroponic vegetable farming. 


We propose to cooperate with any proper institution in order to build a DEMO of the HPVSC technology, as described, in order to exploit jointly the technology under terms that we are ready to discuss with the institution authorities 


The institution will be the owner of the DEMO, which will be raised in a proper land in any proper country, and will cover the construction cost of it, that is estimated to be less than 2.0 million EUROs, including engineering studies, supervision, traveling & accommodation expenses, estimated to 10% of the construction cost of the DEMO.


Main body


Undoubtedly PV parks are the most suitable renewable energy system to solve the planet's energy problem without the side effects of climate change from the use of fossil fuels


PVs, however, have the following disadvantages in particular for massive application in countries with strong solar irradiation such as the Arab countries:




  • Strong solar irradiation increases PV productivity, but as increasing their temperature reduces their efficiency by up to 50%




  • Dust in these sandy countries lands sitting on the surface of PV panels is further reducing their performance




  • So PV panels in these countries need cooling and removing of dust




  • In several countries as well as in several Arabic countries land is valuable and PV solar parks occupy soils that could be used for agriculture for food production




  • In these countries, solar PVs must be suspended high above the ground to leave the arable land [1]




  • In all countries, electricity is needed after the sun, and in the long run solar PVs must be able to operate after the sun. Storage energy for sunset operation in solar PV parks will gradually become necessary and batteries will probably be the ultimate solution




  • With current data, however, Lithium-Ion batteries are expensive and a method should be found to reduce the required amount of batteries for operation after sunset




The HPVSC technology gives a satisfactory answer to all previous problems reported as described below:





  1. The PV panels on the roof rest on water tubes where they transfer part of their thermal load, and these water tubes are cooled by the moving air stream that is continuously escaping from the chimney. 
  2. Alternatively, the water in the tubes could be continuously circulated in an underground tank on the ground, which maintains a constant low temperature 
  3. Roof PV panel rows can be dust-cleaned with special automatic brushes as many times as needed per day 
  4. Translucent glasses that complement the roof can also act as mirrors, further increasing the performance of PVs [2] 
  5. The PVs are suspended on the roof and leave the space beneath them, protected inside the closed greenhouse from outside winds and cooled by the air stream generated by the solar chimney for hydroponic green-housing [3]. That means , arable land is upgraded 
  6. The solar chimney creates a huge air stream [4] which, when needed during the day, can only be used to cool the PV panels and the hydroponic plants.
  7. While this air stream can be used, after the Sunset, to generate electricity with the Power Plant air-turbines. It should be noted that the external winds enhance the operation of the solar chimney 
  8. The generation of electricity after sunset from Air turbines obviously reduces the amount of batteries required to operate the station after sunset 
  9. Water for cooling and cleaning of PV panels can be collected from rainfall (with a proper roof gutter system) 
  10. If the power Plant is within a reasonable distance from the sea or from a brackish source, water for the hydroponics and PV panel cleaning (2,000m3 / year / MW) can be produced by a reverse osmosis desalination unit. 
  11. Of course, if required, the desalination unit can be boosted to produce the required water in the area








We believe that the massive application of HPVSC technology with the accompaniment of batteries, for uninterrupted electricity generation, can become, in a few years, cost competitive with any fossil fuel electricity generation technology.




Especially for Arab countries the choice and development of HPVSC technology is not simply useful it is necessary.




A DEMO as described in the following file can launch a new era for the Arab countries




Prof. Christos D. Papageorgiou




Imperial College PhD














1.0 MW DEMO, of the Hybrid PV + Solar Chimney 


(HPVSC) Technology 


Short description 


The HPVSC technology is a revolutionary version of the conventional solar chimney technology, by which we can generate electricity by PV panels placed on the roof of a proper greenhouse and by air turbines, using the solar chimney air up-drafting effect. Furthermore, the greenhouse of these plants can be used for protected hydroponic vegetable farming. 


The HPVSC technology has been developed by a series of scientific studies experiments of which the most important is shown in video is shown thesmall experimental solar chimney power plant that was raised in Central Greece. 


The proposed HPVSC power plant is shown in the following figures and will comprise of a greenhouse of 20,000 m2, on the roof of which there will be placed PV panels of rating power of 1.0 MW, cooled by water tubes and cleaned by a system of brushes in order to increase their efficiency. 


The glass panels of the roof will be used also as mirrors transferring part of solar irradiation to PV panels that can increase furthermore their electricity output. 


The greenhouse will be connected to a solar chimney of 60 m height and 12.5 m diameter that will up-draft the warm air of the greenhouse, keeping the greenhouse hydroponic plants in proper temperature. 


Furthermore, eight air turbines of 15KW each, placed on the opposite wall to the Solar Chimney will generate also electricity. 


The air turbines will be forced to rotate by the incoming ambient air that is replacing the up-drafting warm air of the Greenhouse through the Solar Chimney. 


The DEMO plant will be accompanied with a Battery pack of 1000 KWh, in order to operate at least 6 hours after the sunset 


It is estimated that the HPVSC power plant will generate annually at least 2,000 MWh/year of electricity in Middle East, Arab peninsula and North Africa 


Inside its greenhouse can be produced approximately 1,000 tons of hydroponic biologic vegetables (tomatoes, peppers etc). 


The demanded land for the power plant will not be more than 24,000 m2 and it should be near the electric grid.


The estimated cost of the proposed HPVSC power plant is approximately 1,800,000 EURO including the cost of detailed engineering studies, supervision and the necessary traveling and accommodation expenses. 


The income by the electricity and the hydroponic farming it is estimated that can repay the cost of the HPVSC plant in less than 10 years. 


The next HPVSC power plants bigger than the DEMO, at least of 50,000 m2 and 2.5 MW PV panels and the respective Battery storage for at least 6 hours of operation after the sunset will cost less than 1.3 million EURO /MW and for a reasonable price of Electricity and Hydroponic vegetables can be repaid in less than 7 years. 


In the following figures the main parts of the proposed HPVSC plant are shown.






1.1 Greenhouse roof made o PV and Glass panels   

1.2 Peripheral wall 

1.3 Air Turbines 

1.4 Greenhouse side door

1.5 Roof of connecting tunnel of Solar Chimney with the Greenhouse 

1.6 Solar Chimney





2.1 Solar Chimney 

2.2 Roof of the tunnel connecting the Solar Chimney with the Greenhouse 

2.3 Exit openings of the up-drafting warm air of the Greenhouse through the Solar Chimney 



3.1 PV panel of a Greenhouse roof section 

3.2 Glass panel of a Greenhouse roof section 

3.3 Water tube for PV panels cooling



4.1 A series of the Greenhouse roof PV panels 

4.2 A series of the Greenhouse roof Glass panels 

4.3 Side wall glass panel 

4.4 Side door of the Greenhouse 

4.5 Rain water collecting tube 

4.6 Side wall panel




5.1 Front wall of the Greenhouse opossite to Solar Chimney 

5.2 Air Turbine 

5.3 Auxiliary window for the incoming ambient air